The Aerosol Physical Characteristics of Desertification Grass Areas in North China during Spring

The physical characteristics of dust aerosol were collected over Zhurihe (ZH) site, which lies on the southwest border of Hunshan Dake sand-land (HDS), by using WPS (wide-range particle spectrometer) model 1000XP during the spring of 2006. Size distributions of particles with 0.5-10.0 mum were examined and the daily mean number concentration of aerosols for the situ periods on non-dusty days was 86.7 cm^-3. It was 1333.08 cm^-3 on windblown dust (WD), 2817.09 cm^-3 on light dust storm (LDS) and 4372.58 cm^-3 on severe dust storm (SDS). Comparing with Sanggen Dalai (SD), which lies in the inner of HDS, observed during IMGRASS (inner-Mongolia semi-arid grass-land atmosphere surface study) of 2001, the average number concentrations of dust aerosol was 3039.5 cm^-3 on SDS , 659.7 cm^-3 on LDS, 198.3 cm^-3 on WD and 27.7 cm^-3 on ND of the inner HDS. The results show that there are more dust aerosols over the board than the inners both on dusty days and non-dusty days, but the mean particles diameter over the inner is larger than the boards.